Roof Top Solar Panels on a Residential Home
Source: Enerdynamics, "Overcoming the Barriers to Rooftop Solar," blog.enerdynamics.com, June 5, 2014

On May 9, 2018 the California Energy Commission voted 5-0 that all new homes built in California will be required to have solar power installations beginning in 2020. California is the first state in the nation to implement such a requirement.

According to a statement by the California Energy Commission, the implementation of the solar power requirement for new homes will cut energy use by 50% and "will reduce greenhouse gas emissions by an amount equivalent to taking 115,000 fossil fuel cars off the road... Under the new standards, nonresidential buildings will use about 30 percent less energy due mainly to lighting upgrades."

Documents released by the Commission estimate the new solar power building standards will raise the cost of new homes in California $10,000 on average, or about $40 per month over a 30-year mortgage; consumers could save an estimated $80 per month on heating, cooling, and lighting bills.

Some experts contend that the new standards are not the most economical or effective way to reduce greenhouse gas emissions. UC Berkeley Professor Severin Borenstein wrote a letter to the Commission stating that "the vast majority of energy economists believe that residential rooftop solar is a much more expensive way to move towards renewable energy than larger solar and wind installations... This [requirement] would be a very expensive way to expand renewables and would not be a cost effective practice that other states and countries could adopt to reduce their own greenhouse gas footprints."

The new solar power rule adopted by the California Energy Commission must now go before the California Building Standards Commission sometime in October or November to be approved. According to NBC News, the California Building Standards Commission typically adopts the Energy Commission's recommendations, and the solar power requirements will very likely be approved.